Abstract

Electrochemical etching processes at different current densities were used to prepare nano porous silicon with different porosities. A series of nanostructures silver/nano porous silicon (NAg/NPSi) active substrate was prepared by an immersion-plating method. Through controlling the current density, the surface-enhanced Raman scattering (SERS) behaviors to crptocyanen (CY) dye were contrastively studied, for a concentration of (10− 5 M), The (SERS) behavior was attributed to the size of the deposited silver nanoparticles on porous layer. The sensitivity of SERS signal increases with increasing the porosity of the porous sample.

The influence of different types of plasmonic gold (Au-NPs) and silver (Ag-NPs) nanoparticles as well as aging on the performance of Surface-Enhanced Raman Scattering (SERS) sensors were studied. The average diameters of Au-NPs and Ag-NPs were about 23 nm and 15 nm, respectively, with a number of laser pulses of about 200. plasmonic nanoparticles were synthesized by laser ablation process in distilled water using a fixed energy laser fluence of about 14 J/cm 2 of Nd-YAG laser, with 1060 nm wavelength and 1 Hz pulse repetition rate. The SERS sensor was carried out by quick drop casting process of plasmonicplasmonic nanoparticles on glass substrates. The morphological aspects and the performance of SERS sensors were investigated by high resolution transmission electron microscopy (HR-TEM) and Raman spectroscopy. All the results indicated the significant dependence of the performance of the sensor on the types of the plasmonic nanoparticles. The obtained Raman signal intensity of Ag-NPs was about 10 5 au compared with 10 3 au for Au-NPs. While, the stability of Au-NPs was much higher than that of Ag-NPs based on SERS sensors due to the normal oxidation process of Ag-NPs.